Oh hey, I'm not alone! So I wrote a script that emulates Reddit's behavior when you have checked the "open links in a new tab" option in your user settings.

Edit: You can apply the code to a bookmarklet, and when you go to old.lemmy and click the bookmarklet, links will behave like you like. The downside is every time you load a new page, you have to click it again.

If you prefer, you can use the same code as a Tampermonkey userscript and it will apply it to the site automagically. I put both versions of the script at this pastebin link:

https://pastebin.com/hiVJW81G